Magnesium alloys, since they are the lightest and the highest in strength-weight ratio among the commonly used structural materials, are attracting attention as energy saving materials for automotive parts. In addition, the needs for reducing the weight, wall thickness and size of cellular information equipment, and the recycling ability make them replace plastic materials and even in a increasing trend. Responsive to the needs like these, Shibaura Machine has developed the fully automated magnesium die casting system. The system of gases that SF6 should exchange in a new gas is constructed.